1. Field of the Invention
The present invention relates to a heat sensitive stencil.
2. Description of the Related Art
Conventionally known is a heat sensitive stencil paper which can be perforated by infrared radiation or a thermal head. A typical example of such a heat sensitive stencil paper is formed by bonding a thermoplastic film and a porous thin paper to each other with use of an adhesive. An example of a stencil printing device employing such a heat sensitive stencil paper is a known single drum type stencil printing device as shown in FIG. 10. Referring to FIG. 10, reference numeral 62 denotes a carrier drum. A perforated heat sensitive stencil paper 64 is wrapped around an outer circumferential surface of the carrier drum 62 in such a manner that a porous carrier of the heat sensitive stencil paper 64 is disposed inside. Ink is supplied from the inside of the carrier drum 62 toward the outer circumferential surface of the carrier drum 62. A press roller 66 is brought into pressure contact with the heat sensitive stencil paper 64 on the carrier drum 62 through a printing paper 68, and the carrier drum 62 is rotationally driven to thereby effect stencil printing on the printing paper 68.
However, the single drum type stencil printing device as mentioned above is large in scale, and it is intended to produce a large amount of prints. Accordingly, in the case of producing a relatively small amount of prints by using this printing device, a running cost is increased.
Another example of a stencil printing device is a known depression type stencil printing device as shown in FIG. 11. Referring to FIG. 11, reference numeral 70 denotes a heat sensitive stencil paper formed by bonding a thermoplastic film to a porous carrier. A frame 72 is provided at an outer peripheral portion of the porous carrier of the heat sensitive stencil paper 70. A cover sheet 74 having an ink impermeability is disposed on the frame 72 to define a recess 84 which is an ink applied portion. Thus, the heat sensitive stencil paper 70, the frame 72 and the cover sheet 74 constitute a heat sensitive stencil 76. The printing device is made of a depression member 78 adapted to be pivotally moved, a base member 80 disposed in opposed relationship to the depression member 78, and a retainer member 82 disposed at an outer peripheral portion of the depression member 78 opposed to the base member 80, for retaining the heat sensitive stencil 76. In operation, ink is first applied to the recess 84 defined by the perforated heat sensitive stencil paper 70 and the frame 72, and the cover sheet 74 is attached to the frame 72 so as to cover the recess 84, thus constructing the heat sensitive stencil 76. Then, the heat sensitive stencil 76 is secured to the depression member 78 by the retainer member 82, and the depression member 78 is pivotally depressed against a printing paper 86 placed on the base member 80.
The depression type stencil printing device as mentioned above can be made compact, but an operator must manually apply the ink. Accordingly, there is a possibility that the operator's hands or the like are stained by the ink in applying the same, or an ink layer thickness is not uniform, causing nonuniformity of print.